Share Based Compensation - Summarized Activity of Cash-Settled Stock Appreciation Rights (Detail) (Stock Appreciation Rights (SARs) [Member], USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at beginning of year	866,000		895,000
Granted, Rights Outstanding	0
Exercised, Rights Outstanding	(285,000)
Forfeited, Rights Outstanding	(1,000)
Balance at end of period	580,000		895,000
Exercisable at end of period, Rights Outstanding	534,000
Non-vested at beginning of year, Weighted Average Grant Date Fair Value	$ 11.38
Granted, Weighted Average Exercise Price	$ 0.00
Exercised, Weighted Average Exercise Price	$ 10.16
Forfeited, Weighted Average Grant Date Fair Value	$ 17.80
Non-vested at end of period, Weighted Average Grant Date Fair Value	$ 11.96
Exercisable at end of period, Weighted Average Exercise Price	$ 11.46
Balance at beginning of year, Weighted Average Remaining Contractual Term	6 years
Balance at end of period, Weighted Average Remaining Contractual Term	5 years
Exercisable at end of period, Weighted Average Remaining Contractual Term	5 years
Aggregate Intrinsic Value	$ 5,400	$ 5,256
Exercisable at end of period, Aggregate Intrinsic Value	$ 5,240